1. Field of the Invention
The present invention relates to hinge assemblies, and particularly to a hinge assembly for a foldable portable electronic device.
2. Description of Prior Art
With the development of the technologies of wireless communication and information processing, portable electronic devices such as mobile phones and PDAs (Personal Digital Assistants) are now in widespread use. These portable electronic devices enable consumers to enjoy the convenience of high technology services anytime and anywhere. Foldable mobile telephones are particularly favored by consumers for their comprehensive useful and amusing features.
Conventionally, a hinge assembly for a foldable portable device includes two barrel portions, which are provided respectively in a main body case and in a flip case of the foldable portable device. A central hinge pin movably fixes the barrel portions together. The flip case is thus rotatably connected to the main body case by the hinge assembly.
With the conventional hinge assembly as described above, two hands are generally needed to rotatingly open the flip case up from the main body case. One hand is used to hold the main body case, and the other hand rotates the flip case up. This can be inconvenient for a user who is busy doing other things at the same time.
U.S. Pat. No. 6,459,887 issued at Oct. 1, 2002 provides a hinge assembly to solve the above problem. As represented in FIG. 6, the hinge assembly relies on a manual button to open the flip case conveniently. There are two barrel portions 13′, 22′ respectively provided in a main body case 1′ and in a flip case 2′ of a foldable telephone, and the hinge assembly 4′ is inserted through the barrel portions 13′, 22′. The hinge assembly 4′ has a manual button 41′ protruding from the barrel portion 13′. The hinge assembly 4′ is substantially in the form of a round rod, and includes a case drive member 43′ and a main body drive member 44′. The case drive member 43′ and the main body drive member 44′ are each in the form of a hollow cylinder, are coaxially engaged with each other, and are axially movably relative to each other and rotatable relative to each other. Cam faces 6′, 61′ in slidable contact with each other are formed in mutually opposing positions of the case drive member 43′ and the main body drive member 44′.
The case drive member 43′ is provided with a pair of projections 48′ on an outer periphery thereof. The projections 48′ are circumferentially spaced apart, and are engaged in an inner periphery of the barrel portion 22′ of the flip case 2′, so that the case drive member 43′ is rotatable with the flip case 2′. Further, the main body drive member 44′ is provided with a pair of projections 47′ on an outer periphery thereof. The projections 47′ are circumferentially spaced apart and engaged in an inner periphery of the barrel portion 13′ of the main body case 1′, so that the main body drive member 44′ is rotatable with the main body case 1′.
The hinge assembly 4′ further includes a tubular member 42′, a shank 45′, a prime mover spring 5′, and an auxiliary spring 51′. The tubular member 42′ has a right end with the manual button 41′ fixed thereto, and a left end extending through a flange 44b′ of the main body drive member 44′ and the auxiliary spring 51′ and in slidable contact with the case drive member 43′.
The flip case 2′ can be opened to a fully open position at the press of the manual button 41′. However, the shank 45′ extends leftward from the left side face of the flange 44b′, and a discoid flange 46′ is provided at the left end of the shank 45′. The hinge assembly is not easy to manufacture and assemble.
In view of the above-described shortcomings, a new hinge assembly is desired. In particular, a hinge assembly providing convenient operation and easy manufacturing and assembly is desired.